gecko-dev/xpcom/io/nsEscape.h

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/* First checked in on 98/12/03 by John R. McMullen, derived from net.h/mkparse.c. */
#ifndef _ESCAPE_H_
#define _ESCAPE_H_
#include "nscore.h"
#include "nsError.h"
#include "nsString.h"
/**
* Valid mask values for nsEscape
* Note: these values are copied in nsINetUtil.idl. Any changes should be kept
* in sync.
*/
typedef enum {
url_All = 0, // %-escape every byte unconditionally
url_XAlphas = 1u << 0, // Normal escape - leave alphas intact, escape the rest
url_XPAlphas = 1u << 1, // As url_XAlphas, but convert spaces (0x20) to '+' and plus to %2B
url_Path = 1u << 2 // As url_XAlphas, but don't escape slash ('/')
} nsEscapeMask;
#ifdef __cplusplus
extern "C" {
#endif
/**
* Escape the given string according to mask
* @param aSstr The string to escape
* @param aLength The length of the string to escape
* @param aOutputLen A pointer that will be used to store the length of the
* output string, if not null
* @param aMask How to escape the string
* @return A newly allocated escaped string that must be free'd with
* nsCRT::free, or null on failure
* @note: Please, don't use this function. Use NS_Escape instead!
*/
char* nsEscape(const char* aStr, size_t aLength, size_t* aOutputLen,
nsEscapeMask aMask);
/**
* Decodes '%'-escaped hex codes into character values, modifies the parameter,
* returns the same buffer
*/
char* nsUnescape(char* aStr);
/**
* Decodes '%'-escaped hex codes into character values, modifies the parameter
* buffer, returns the length of the result (result may contain \0's).
*/
int32_t nsUnescapeCount(char* aStr);
#ifdef __cplusplus
}
#endif
/**
* Infallibly append aSrc to aDst, escaping chars that are problematic for HTML
* display.
*/
void nsAppendEscapedHTML(const nsACString& aSrc, nsACString& aDst);
/**
* NS_EscapeURL/NS_UnescapeURL constants for |flags| parameter:
*
* Note: These values are copied to nsINetUtil.idl
* Any changes should be kept in sync
*/
enum EscapeMask {
/** url components **/
esc_Scheme = 1u << 0,
esc_Username = 1u << 1,
esc_Password = 1u << 2,
esc_Host = 1u << 3,
esc_Directory = 1u << 4,
esc_FileBaseName = 1u << 5,
esc_FileExtension = 1u << 6,
esc_FilePath = esc_Directory | esc_FileBaseName | esc_FileExtension,
esc_Param = 1u << 7,
esc_Query = 1u << 8,
esc_Ref = 1u << 9,
/** special flags **/
esc_Minimal = esc_Scheme | esc_Username | esc_Password | esc_Host | esc_FilePath | esc_Param | esc_Query | esc_Ref,
esc_Forced = 1u << 10, /* forces escaping of existing escape sequences */
esc_OnlyASCII = 1u << 11, /* causes non-ascii octets to be skipped */
esc_OnlyNonASCII = 1u << 12, /* causes _graphic_ ascii octets (0x20-0x7E)
* to be skipped when escaping. causes all
* ascii octets (<= 0x7F) to be skipped when unescaping */
esc_AlwaysCopy = 1u << 13, /* copy input to result buf even if escaping is unnecessary */
esc_Colon = 1u << 14, /* forces escape of colon */
esc_SkipControl = 1u << 15, /* skips C0 and DEL from unescaping */
esc_Spaces = 1u << 16 /* forces escape of spaces */
};
/**
* NS_EscapeURL
*
* Escapes invalid char's in an URL segment. Has no side-effect if the URL
* segment is already escaped, unless aFlags has the esc_Forced bit in which
* case % will also be escaped. Iff some part of aStr is escaped is the
* final result appended to aResult. You can also request that aStr is
* always appended to aResult with esc_AlwaysCopy.
*
* @param aStr url segment string
* @param aLen url segment string length (-1 if unknown)
* @param aFlags url segment type flag (see EscapeMask above)
* @param aResult result buffer, untouched if aStr is already escaped unless
* aFlags has esc_AlwaysCopy
*
* @return true if aResult was written to (i.e. at least one character was
* escaped or esc_AlwaysCopy was requested), false otherwise.
*/
bool NS_EscapeURL(const char* aStr,
int32_t aLen,
uint32_t aFlags,
nsACString& aResult);
/**
* Expands URL escape sequences... beware embedded null bytes!
*
* @param aStr url string to unescape
* @param aLen length of aStr
* @param aFlags only esc_OnlyNonASCII, esc_SkipControl and esc_AlwaysCopy
* are recognized
* @param aResult result buffer, untouched if aStr is already unescaped unless
* aFlags has esc_AlwaysCopy
*
* @return true if aResult was written to (i.e. at least one character was
* unescaped or esc_AlwaysCopy was requested), false otherwise.
*/
bool NS_UnescapeURL(const char* aStr,
int32_t aLen,
uint32_t aFlags,
nsACString& aResult);
/**
* Fallible version of |NS_UnescapeURL|. See above for details.
*
* @param aAppended Out param: true if aResult was written to (i.e. at least
* one character was unescaped or esc_AlwaysCopy was
* requested), false otherwise.
*/
nsresult NS_UnescapeURL(const char* aStr,
int32_t aLen,
uint32_t aFlags,
nsACString& aResult,
bool& aAppended,
const mozilla::fallible_t&);
/** returns resultant string length **/
inline int32_t
NS_UnescapeURL(char* aStr)
{
return nsUnescapeCount(aStr);
}
/**
* String friendly versions...
*/
inline const nsACString&
NS_EscapeURL(const nsACString& aStr, uint32_t aFlags, nsACString& aResult)
{
if (NS_EscapeURL(aStr.Data(), aStr.Length(), aFlags, aResult)) {
return aResult;
}
return aStr;
}
/**
* Fallible version of NS_EscapeURL. On success aResult will point to either
* the original string or an escaped copy.
*/
nsresult
NS_EscapeURL(const nsACString& aStr, uint32_t aFlags, nsACString& aResult,
const mozilla::fallible_t&);
// Forward declaration for nsASCIIMask.h
typedef std::array<bool, 128> ASCIIMaskArray;
/**
* The same as NS_EscapeURL, except it also filters out characters that match
* aFilterMask.
*/
nsresult
NS_EscapeAndFilterURL(const nsACString& aStr, uint32_t aFlags,
const ASCIIMaskArray* aFilterMask,
nsACString& aResult, const mozilla::fallible_t&);
inline const nsACString&
NS_UnescapeURL(const nsACString& aStr, uint32_t aFlags, nsACString& aResult)
{
if (NS_UnescapeURL(aStr.Data(), aStr.Length(), aFlags, aResult)) {
return aResult;
}
return aStr;
}
const nsAString&
NS_EscapeURL(const nsAString& aStr, uint32_t aFlags, nsAString& aResult);
/**
* Percent-escapes all characters in aStr that occurs in aForbidden.
* @param aStr the input URL string
* @param aForbidden the characters that should be escaped if found in aStr
* @note that aForbidden MUST be sorted (low to high)
* @param aResult the result if some characters were escaped
* @return aResult if some characters were escaped, or aStr otherwise (aResult
* is unmodified in that case)
*/
const nsAString&
NS_EscapeURL(const nsString& aStr, const nsTArray<char16_t>& aForbidden,
nsAString& aResult);
/**
* CString version of nsEscape. Returns true on success, false
* on out of memory. To reverse this function, use NS_UnescapeURL.
*/
inline bool
NS_Escape(const nsACString& aOriginal, nsACString& aEscaped,
nsEscapeMask aMask)
{
size_t escLen = 0;
char* esc = nsEscape(aOriginal.BeginReading(), aOriginal.Length(), &escLen,
aMask);
if (! esc) {
return false;
}
aEscaped.Adopt(esc, escLen);
return true;
}
/**
* Inline unescape of mutable string object.
*/
inline nsACString&
NS_UnescapeURL(nsACString& aStr)
{
aStr.SetLength(nsUnescapeCount(aStr.BeginWriting()));
return aStr;
}
#endif // _ESCAPE_H_